A bit too early to know that. Random bombing is how islamo-fascists work, and these two bombs are an attack on government. Islamo-facism terror remains a strong possiblility until a "normal" anglo nut case is shown to be merely angry at government, and not religously motivated.
Only one catch, which is that Islamofacists view any government besides the Koran interpreters as infidel. Even democracy (maybe especially democracy) allows autonomy enough to be a threat to an Islamic state form of society.